增程器气门弹簧断裂原因分析  

Fracture causes analysis of the valve spring of a range extender

作　　者：秦渐津 杨青 王小琴 李政 QIN Jianjin;YANG Qing;WANG Xiaoqin;LI Zheng(Chongqing SERES New Energy Vehicle Design Institute Co.,Ltd.,Chongqing 401120,China)

机构地区：[1]重庆赛力斯新能源汽车设计院有限公司,重庆401120

出　　处：《柴油机设计与制造》2024年第3期45-48,共4页Design and Manufacture of Diesel Engine

摘　　要：某增程器气门弹簧在服役早期连续发生了多次断裂,采用外观检查、断口分析、能谱分析、硬度测试、金相分析和化学成分分析等方法分析了断裂原因。结果表明:该弹簧原始存在的折叠类缺陷是其疲劳断裂的裂纹源,折叠缺陷的存在使折叠尖端处应力集中,在交变载荷作用下,成为疲劳裂纹源并不断扩展,最终断裂失效。Springs of a range extender experienced multiple consecutive fractures in the early stages of service.The fracture causes of the spring were analyzed by means of macro observation,fracture analysis,energy spectrum analysis,hardness testing,metallographic examination and chemical composition analysis.The results show that the folding defects that originally existed in the spring became the crack source for its fatigue fracture.Folding defect causes stress concentration at the folding tip,which becomes a source of fatigue cracks under alternating loads and continues to propagate,ultimately lead to fracture failure.

关 键 词：增程器 气门弹簧 断裂 折叠 裂纹源 

分 类 号：TH135[机械工程—机械制造及自动化] TG111.91[金属学及工艺—物理冶金]